The Soviet Union invades Finland starting what is sometimes call the "Winter War". Though small and under-resourced, the Finnish Army was resilient, well-led and was able to use knowledge of the terrain to good effect.
Despite the overwhelming odds, Finland resisted for three months with little outside assistance. However, it was only a matter of time before the balance of power tipped in the Soviet Union’s favor. Finland was forced to sign the Treaty of Moscow on 12 March 1940, which ceded 11 per cent of its territory to the Soviet Union. More